Propulsion arrangement for watercraft

ABSTRACT

A marine vessel, having a concavity in the bottom of the hull, proximate to the bow, is propelled in water by the oscillatory motion of a propeller blade which is attached to the underside of the vessel and pumps water into and from the concavity. Instead of one propeller blade, a plurality of blades may be arranged side by side or in tandem.

United States Patent [72] Inventors Heinrich Hertel Tannenbergallee 36,1 Berlin 19, Germany; Klaus Affeld, Wisebadenerstrasse 85, 1 Berlin 41,Germany [211 App]. No. 797,482

[22] Filed Feb. 7, 1969 [45] Patented Feb. 23, 1971 [32] Priority Feb.8, 1968 [33] Germany [31] P 15 81 104.8

[54] PROPULSION ARRANGEMENT FOR [51] Int. Cl B63h H30 [50] Field ofSearch l 15/28 [56] References Cited UNITED STATES PATENTS 3,453,9817/1969 Gause 115/28 Primary Examiner-Andrew H. Farrell Attorney-MichaelS. Striker ABSTRACT: A marine vessel, having a concavity in the bottomof the hull, proximate to the bow, is propelled in water by theoscillatory motion of a propeller blade which is attached to theunderside of the vessel and pumps water into and from the concavity.Instead of one propeller blade, a plurality of blades may be arrangedside by side or in tandem.

1 PROPULSION ARRANGEMENT FOR WATERCRAFT BACKGROUND OF THE INVENTIONSUMMARY or THE INVENTION The novel feature of the invention resides inthe installation of a propeller at the underside of the vessel proximateto the how so that, in one of its positions, the blade is almostcompletely withdrawninto a concavity fonned in the bottom of the hull.In one presently preferred embodiment the bow of the vessel is extendedbelow the level of the keel and outlines a recess in which the propellerblade is receivable.

A vessel incorporating the propulsion arrangement of the presentinvention is well adapted forpassing through shallow waters havingsubmerged sandbanks. The pumping motion executed by the propeller sucks-up sand and clears a channel through which the vessel may proceed. Theextension of the bow below the keel prevents the sucking in of air, sothat the efficiency of the propulsion arrangement is increased.

In one presently preferred embodiment of the invention the vessel isprovided with one propeller of substantially the same blade length asthe width of the hull. This arrangement is particularly satisfactorywhen the sandbanks are wider than the vessel. In another preferredembodiment a plurality of separate blades are disposed side by sideacross the width of the hull. The blades may be of the same or ofdifferent size and oscillate at the same or at different speeds. In thelatter case differential speeds may be coordinated with the steeringcontrols of the vessel.

The novel features which are considered as characteristic for theinvention are set forth inparticular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a longitudinal sectional viewof the bow portion of a vessel embodying one form of the improvedpropulsion arrangement;

FIG. 2 is a cross-sectional view of the vessel as seen in the directionof arrows from the line 26 in FIG. 1;

FIG. 3 is a longitudinal sectional view of the bow portion of a vesselwherein the propulsion arrangement comprises two propellers in tandem;and 1 FIG. 4 is a cross-sectional view of the bow of a vessel with threepropellers side by side.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. I there is shown'thehull l of a vessel which has at its underside a concavity 4, extendingfrom the bottom of the hull toward the interior of the vessels body. Apropeller blade 2 in the concavity 4 has a rear end 10 pivotally mountedwith clearance on the hull l for movement about a horizontal axis normalto the longitudinal axis of the vessel. The front end of the blade 2 isarticulately attached-to a shaft 3 which is actuatable by drive meanssuch as, for example, a Diesel engine (not shown) to move up and down asindicated by the arrow 9. The movements of shaft 3 cause the blade 2 tooscillate about its rear end 10 and to move toward, and away from, thewall 12 in the interior of the concavity 4. The body of the vesselitself, and detent means 7 prevent excessive displacement of the rearend 10 of the blade 2 The pumping motion of the oscillating blade 2produces a stream which is indicated by the arrow 11 whereby the vesselmoves in opposite direction. An extension of the bow 5 below the levelof the keel of the vessel, as well as the side walls 8 of the hull,prevent air from being sucked in during the intake stroke. Rocks or sand6 scooped up during the upward stroke of the blade 2 are harmlesslydeflected from the blade surface remote from the wall 12, since thespeed at which the blade moves is slower than the speed of the fluidflow.

FIG. 2 shows that the length of the propeller blade 2 is approximatelyequal to the width of hull l. The reference numerals 25 denote verticalguides for the shaft 3.

The vessel shown in FIG. 3 has two concavities respectively denoted by4a and 4b in the bottom of the hull. Propeller blade 2a is movable inconcavity 4a and propeller blade 2b is movable in concavity 4b atcoordinated or separate speeds relative to each other.

According to FIG. 4 each of three propeller blades denoted by thenumerals l3, l4 and 15 respectively, is disposed in a separatecompartment denoted by numerals I6, 17 and I8 and separated from theadjacent blade or blades by the walls 19 and 20. Blade 13, mounted onthe drive shaft 21, blade 14 on drive shaft 22, and blade 15 on driveshaft 23, are movable at different speeds in the direction of the arrows27, 28 and 29. Vertical guides 25 for the respective drive shafts areprovided in each of the compartments 16, 17 and I8.

If, for example, blade 15 has a greater and blade 13 a lesserup-and-down speed, as indicated by the relative lengths of the arrows27, 28 and 29, the vessel will turn about an imaginary axis such as theline indicated by the numeral 24.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofmarine propulsion arrangement for watercraft of the type propelled in afluid medium and having propeller blades mounted on a horizontal axisdiffering from the types described above.

We claim:

l. A marine propulsion arrangement for watercraft, comprising a hullhaving a bottom part provided with a submerged concavity adjacent to thebow, propeller blade means having a rear end and a front end, said rearend being movably attached to the underside of said hull and said frontend being movable in said concavity up and down to thereby pump waterinto and from said concavity, and means for moving said front end.

2. A marine propulsion arrangement as defined in claim I wherein saidpropeller blade means is movable into a position contiguous with aportion of said bottom part inside said concavity.

3. A marine propulsion arrangement as defined in claim I, furthercomprising a projection on said bow extending substantially verticallydownwardly in front of said concavity.

4. A marine propulsion arrangement as defined in claim I wherein saidmeans for moving said front end of said propeller blade means includes ashaft extending in a direction which is substantially normal to thelongitudinal axis of said vessel.

5. A marine propulsion arrangement as defined in claim 4 comprisingvertical guides for said shaft.

6. A marine propulsion arrangement as defined in claim 1, furthercomprising detent means for restricting movement of said rear end ofsaid propeller blade means.

7. A marine propulsion arrangement as defined in claim I wherein saidblade means comprises a blade whose length is substantially equal to thewidth of said hull.

8. A marine propulsion arrangement as defined in claim I wherein saidblade meanscomprises a plurality of blades arranged in tandem, and saidconcavity includes separate concavities for said blades.

9. A marine propulsion arrangement as defined in claim I wherein saidblade means comprises a plurality of blades disposed side by side.

10. A marine propulsion arrangement as defined in claim 9 wherein saidplurality of blades is disposed across the entire width of said hull.

11. A marine propulsion arrangement as defined in claim 10 wherein eachof said blades is movable at a speed different from the speed of theother blades.

1. A marine propulsion arrangement for watercraft, comprising a hullhaving a bottom part provided with a submerged concavity adjacent to thebow, propeller blade means having a rear end and a front end, said rearend being movably attached to the underside of said hull and said frontend being movable in said concavity up and down to thereby pump waterinto and from said concavity, and means for moving said front end.
 2. Amarine propulsion arrangement as defined in claim 1 wherein saidpropeller blade means is movable into a position contiguous with aportion of said bottom part inside said concavity.
 3. A marinepropulsion arrangement as defined in claim 1, further comprising aprojection on said bow extending substantially vertically downwardly infront of said concavity.
 4. A marine propulsion arrangement as definedin claim 1 wherein said means for moving said front end of saidpropeller blade means includes a shaft extending in a direction which issubstantially normal to the longitudinal axis of said vessel.
 5. Amarine propulsion arrangement as defined in claim 4 comprising verticalguides for said shaft.
 6. A marine propulsion arrangement as defined inclaim 1, further comprising detent means for restricting movement ofsaid rear end of said propeller blade means.
 7. A marine propulsionarrangement as defined in claim 1 wherein said blade means comprises ablade whose length is substantially equal to the width of said hull. 8.A marine propulsion arrangement as defined in claim 1 wherein said blademeans comprises a pluralitY of blades arranged in tandem, and saidconcavity includes separate concavities for said blades.
 9. A marinepropulsion arrangement as defined in claim 1 wherein said blade meanscomprises a plurality of blades disposed side by side.
 10. A marinepropulsion arrangement as defined in claim 9 wherein said plurality ofblades is disposed across the entire width of said hull.
 11. A marinepropulsion arrangement as defined in claim 10 wherein each of saidblades is movable at a speed different from the speed of the otherblades.